Improving coverage is an on-going endeavor of wireless service providers. To achieve ubiquitous coverage, service providers generally install more base stations or access points in a given geographical area. These base stations or access points (hereafter, collectively “base stations”) often include micro-base stations (or pico-base stations) to provide localized area coverage or indoor coverage for common wireless standards such as CDMA2000-1x, WCDMA, and GSM. Micro/Pico-base stations are expected to play a significant role in future deployments of other standards (e.g., 802.16e) and in the development of fourth generation standards.
However, widespread deployment of micro-base stations and pico-base stations (hereafter, collectively “micro-base stations”) is hindered by the relatively high costs associated with any type of wireless network infrastructure components, including base stations. Base stations are designed to meet more stringent RF requirements than mobile stations (also called “wireless terminals”, “handsets”, and the like). Moreover, the number of base stations (and other infrastructure components) that are manufactured is always much smaller than the number of mobile stations. This problem is further exacerbated by the use of different transceiver architectures to communicate according to different standards. The total number of base stations that are manufactured is subdivided into still smaller categories of base stations that operate under different standards (i.e., CDMA, GSM, etc.) Spreading the high design costs over the relatively low manufacturing volume means that base stations are much higher in price than mobile stations.
Thus, base stations for wide area networks (i.e., cell phone networks) often cost many tens of thousands (or even a few hundred thousand) dollars. Micro-base stations for small office-home office (SOHO) environments typically cost on the order of thousands of dollars each. As a result, micro-base stations have seen limited deployment in SOHO environments.
Base stations, including micro-base stations, are generally implemented using a mix of application specific integrated circuit (ASIC) devices and discrete components. Generally, the modem circuitry of the base transceiver subsystem (BTS) section in the base station is implemented via an ASIC or a field programmable gate array (FPGA). The remaining major functional blocks (e.g., network interface, radio transceiver, and radio frequency (RF) front-end, etc.) of the base station are implemented using discrete components.
The major impediments to the development of a low-cost base station include the cost of the RF transceiver, the cost of providing accurate timing references (e.g., GPS), particularly for CDMA and WCDMA, and the cost of backhaul networks. The state-of-the-art for micro-BTS systems (e.g., Samsung SpotBTS, Infomoble PicoBTS, Nokia Insite BTS, and the like) consists of multi-board assemblies. This includes multi-board assemblies even for a single carrier omni BTS, such as the InfoMobile PicoBTS. The prior art base stations also use discrete component implementations for the RF chains and unique hardware (NPU, CPU, modem, FEM) designs for each wireless standard and frequency band.
Currently, there is no single board implementation of a complete base station for the major mobile wireless standards (i.e., CDMA2000-1x, GSM, WCDMA, etc.). There are single board implementations for WLAN applications, such as 802.11a/b/g, but the architectures and devices used to implement 802.11x products cannot be adapted for use in mobile wireless standards. Development of an RF ASIC for each wireless standard is cost prohibitive and not cost competitive with equivalent mobile station solutions.
Therefore, there is a need in the art for an improved base station for use in a wireless network. In particular, there is a need for an improved micro-base station having a low-cost micro-BTS section for use in the small office-home office (SOHO) environment.